Fig. 2.

Transgenic mouse lines expressing carbonic anhydrase III (CAIII) in the heart. Adult heart-specific expression of CAIII was produced in mice engineered by introducing an α-myosin heavy chain (MHC) promotor-driven transgene. Two stable transgenic mouse lines were generated with low and high physiological levels of CAIII expression (lines 8215 and 8232, respectively) as confirmed with mAb CP3 Western blot of cardiac muscle protein extracts and densitometric analysis. The transgenic and wild-type control mouse hearts showed similar patterns of overall protein expression in the SDS-gel (A). Transgenic mouse line 8232, with a higher level of expression in hemizygotes (Hemi) at ~50% of the level in soleus muscle (B), was used for functional studies. Line 8232 homozygotes (Homo) expressed a higher level of CAIII in the heart reaching the level in soleus muscle (A) with no detectable negative impact (data not shown). Values are presented as means ± SE. Car3, carbonic anhydrase III gene.